Impact rotary drill.



W H. WAKFER.

IMPACT ROTARY DRILL.

APPLICATION FILED mm: I6. 1913.

Patented Apr. 27, 1915.

2 SHEETS-SHEET 1.

FIG. 6. FIG. 7.

FIG. I.

W.- H. WAKFER.

IMPACT ROTARY DRILL. APPLICATION FILED JUNE :6. 191a.

. Patented Apr. 27, 1915.

2 SHEETSSHEET 2- bef UNITED STATES PATENT OFFICE.

HENRY WAKI'EB, Q1 SOUTH NOBWOOD, ENGLAND, ASSIGNOR OF ONE-HAL] '10 mum. PECK, OF WALLINGTON, ENGLAND.

ntracr Romany DRILL.

specification of Letters Patent.

Patented Apr. 2'7, 1915.

Application filed June 16, 1913. Serial No. 773,894.

To all whom it may concern: I

Beit known that I, WILLIAM HENRY \VAKFER, a subject of the King of Great Britain, and resident of 67 Whitworth road, South Norwood, in the county of Surrey, England, have invented new and useful Improvements in Impact Rota l'y DIlllS, of which the following is a speci cation.

This invention comprises improvements in andrelating to percussive rock-drills, bits and like appliances for boring in earth, rock and the like and has for its object to provide drills or bits which can be manufactured cheaply and are more efficient in operation and entail less cost in respect of maintaining them in an efiicient condition than drills or bits heretofore in use. According to this invention the cutting or boring head of the percussive drill steel is solid or prismatic and at the end is formed with three or more cutting edges which meet at the point of the tool, three or more triangular faces being bounded by the said edges. These faces may be flat, or concave or otherwise suitably formed and are preferably continuations of the flat hollow or fluted sides of the prismatic head. The cutting or boring heads thus fashioned may be formed as separate heads or bits adapted to be connected to the body or bar of the drill by means for example of a sleeve coupling or of a socket in one with the body of the drill bar or in one with the bit, as hereinafter described, or the heads or bits may ormed on or welded on the end of the body or bar of the drill.

In order to enable this invention to be readily understood reference is made to the accompanying drawings in which various examples are illustrated and wherein:

Figure l is a side elevation of a simple form of the improved drilling or boring tool when made three sided. Fig. 2 is a plan of Fig. 1. Fig. 3 is a side elevation and Fig. 4 is a plan of a four sided tool or hit; Fig. 5 is partly a cross section and partly a rear end elevation of a tool the head of which may be similar to that shown in Figs. 3 and 4 but the body or bar of which is formed with helical ribs. Fig. 6 is a sectional elevation of a head or bit coupled by means of a sleeve to the drill bar or body. Fig. 7 is a view similar to Fig. 6 the plane of the section being at right-angles to the lane of the. section Fig. 6. Fig. 8 is a plan o Fig.

{3. Fig. 9Tis' a view similar to Fig. 7 but illustrating a modified coupling arrange- Fig.-10l is a sectional elevation thesection being taken on the 11 Fig. 9. Fig. 11' isan elevation of an'appliapce employed for facilitating the removal 0 socket on the end of the bar and Fig. 14 is a similar View showing the head formed {)vith a socket for receiving the end of the In producing the construction shown in Figs. 1 and 2 a bar a of steel of suitable section, such as the triangular section shown, be hammered or otherwise formed or fashioned at the end prismatic head Z7 is produced. The prism shown is three-sided, and at one end is joined to, or in one with, the bar a and the opposite end is formed as a three sided pyramid c, the sides of the pyramid being preferably continuations of the sides of the prism. With this three-sided form of head or bit the cutting edges d bounding the sides of the pyramid are sharper than is the case when a pyramid having a greater num ber of sides is employed, because the angles of the triangular base are more acute than the angles of a rectangular or polygonal base. Nevertheless, as already mentioned and as seen in Figs. 3, 4 and 5, heads or bits 6 0 having four sides and four cutting edges 03 may be employed. Or heads having even more than four sides and cutting edges may be produced. The corners of the prismatic portion of the head or bit may be flattened or rounded if desired as indicated by the reference letter e. It will be readily understood that the head a may be formed from a short length of steel which-may be welded to the body or bar of the drill steel, or such head maybe formed at one extremity of a. barlof suitable length for serving as a drill stee In the case of a separate head or hit, this is formed on a short length of steel and the portion 7, Figs. 3, 6, 7 and 9 not formed into so that a thickened the thickened head, which may be termed bar. For example this re-,

sleeve 9 if a sleeve preferred. The pins h 0 may be tapered so that they may be readily nand driven in from one side of the sleeve and driven out by a blow struck from the opposite side. It may be preferable to avold a sharp angle at the junction between the head b and the bar a or reduced portion f, as for example b forming the curved portion m Fi s. 1 an 3.

f desired the reduced and of the head may be interlocked with the end of the bar Z within the sleeve 9 by an interlocking tongue oove 0, or other interlocking devices forme on such ends.

As an alternative, the ends of the portion f and bar Z may be of triangular or other angular cross section and the coupling sleeve or socket ma be similarly formed or may be forme wit a similar angular bore as seen for example in Figs. 9 and 10 wherein a sleeve of triangular cross-section is illustrated. It is preferred to employ the securing pins h as above described so that the head'or bit b 0 cannot be left in a hole or fissure when withdrawing the bar Z. It is obvious that the sleeve 9 may be formedas a socket g on the end of the bar Z as shown in Fig. 13. As an alternative and as seen in Fig. 14, the bar Z of any cross-section may'be tapered, if desired, and inserted into a socket or recess formed in the head I; and securing pins may be used as before. desired the bar Z may be mainly of circular cross section and the end only need be of angular cross section.

When it is desired to deliver air or water at or near the point of the drill, one or more holes Z) may be drilled at an angle into the head so as to meet a central bore g which terminates at a suitable distance. in the rear of the p is drilled from each face of the pyramidal cuttin -end at such an angle as to meet the centra bore sa at'the point r Fig. 7, although such ho e'or holes may be drilled at an angle into the fiat, hollow or fluted faces of the prism b as indicated in Figs. 1 and 3. The bar Z of the drill may be formed with helical or twisted ribs indicated by dotted lines a in Fig. .6 and shown in full lines 'gfb, orthe bars Z may be of any angular' oss section and may be twisted. For examplethe an lar' bar a in Fig. 1 may be helically twiste as indicated by the dotted ,lines' t n Fig. 1. Preferably the number of ibs ai or' the' number of sides of the barn, is the same as the number of sides-of the prispoint of the drill. Preferably a hole matic head. The ribs 3, or the twist, aforesaid serve or serves to feedback to the mouth of the drill-hole the cuttings or debris roduced by the operation of the cutting e ges d of the drill. I

The coupling sleeve or socket g may be formed with helical or twisted ribs or pro- 'ections as. indicated bydotted lines it in ig. 6, or if the sleeve g is angular as in Fig. 9, it may itself be twisted so that the conveyance of the cuttings or debr s takes place immediately from the rear of the cutting head 12.

When a separate head or hit is emplo ed,

the same may be released from the coup mg sleeve by means of a driver or tom ny '0 which may be U-shaped as seen in Fig. 11 and tapered or of wedge form as seen in Fi 12. This device is placed astride the re uced end f of the head b between the end of the sleeve g and the rear end of the enlarged head I) and, when the appliance 'v is driven on, it loosens or ejects t 0 head I) in or from the sleeve 9. The reduced end f of the head may of course be tapered as seen in Fig. 3 and the bore of the sleeve or socket 9 may be similarly formed.

Figs. 3 and 4 clearly show at w how the sides of the prismatic head 7) may be hollowed out for facilitating the working of the drill. It is preferable to gently taper the head I) from the cutting end toward the rear or reduced end f as shown in the various fi'gures.

It will now be evident that whenever the edges d become blunt or broken, it is an easy operation to remove one head or bit 6 c and to substitute another therefor, if the coupling sleeve is employed. In any case it is a simple matter to sharpen the edges d, (whether the head I) o be integral with a tool bar a, or with only a connecting reduced portion f) by applying the faces 0 the pyramid c to a stone and grindin such faces until the desired edges are pro need. This offers great advantages as compared with the procedure in sharpening an ordinaryv drill, which requires skill and time both for sharpening and re-tempering or fettling the cutting head of the tool.

What I claim is 1. An impact rotary drill comprising a prismatic head of larger cross sectional dimensions than the shank or bar. upon which it is carried, said head having a short pointed end' the faces of which meet in edges having a length. substantially equivalent tothat of the base of said faces, whereby the edges of the faces perform a cutting operation during rotation.

2. An impact rotary drill comprising a prismatic head of larger cross sectional diranii'dal end, the faces of w are'inefih'ed at such an angle to the base of the pyramid that the edges of said faces form substantially equilateral triangles, whereby the edges of the faces perform a cutting operation during rotation.

impact rotary drill comprising a prismatic head of larger cross sectional dimensions than the shank or bar upon which it is carried, said head bein formed with hollow or concaved sides an substantiall equilateral triangles, whereby the edges 0 the faces perform a cutting operation during rotation.

4. An impact rotary drill comprising a prismatic head of larger cross sectional dimensions than the shank or bar upon which it is carried, said head having a short pyramidal point formed on one end, the sides of the yramid being continuations of the sides 01 the prism, of the sides of said pyramid bein such that the edges of said sides form su stantially equilateral triangles, whereby the ed s of the sides perform a cutting operation (hiring the angle of inclinationrotation, and means formed on the other end of said head for attaching said head to a shank or bar.

5. An impact rotary drill, comprising a prismatic head of larger cross sectional dimensions than the shank or bar u on which it is carried, said head having a s ort point formed on one end, the converging edges of the sides of said end forming substantially equilateral triangles, said point being adapted to penetrate under impactand to cut during rotation, and a tapered shank portion on the opposite end of said head.

An impact rotary drill, comprising a tapering shank, a short prismatic head on the flaring end of said shank and of larger cross sectional dimensions than said shank, said head having grooves formed in its sides and a pyramidal point formed on its end, the edges of the sides of said end forming substantially equilateral triangles, whereby the point is adapted to penetrate under impact and to cut durm rotation.

WILLIAM Hi ENRY WAKFER. itnesses:

W. MoRBnY,

H. D. J AMESON. 

